Collapsible form.



M. S..JAGKSON.

GOLLAPSIBLE FORM.

APPLICATION FILED JULY 26, 1909 Patented Dec. 27: 1910.

Invenfor fie]. ,1 am

MERRILL S. JACKSON, 0F HARTFORD, CONNECTICUT.

COLLAPSIBLE FORM.

Specification of Letters-Patent.

Application filed. July 26, 1909.

Patented Dec. 2'7, 1910.

Serial No. 509,740.

T 0 all whom it may concern:

Be it known that I, MERRILL S. J ACKSON, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in C01- lapsible Forms, of which the following is a specification.

The ob 'ect of my invention is to provide a device of the class specified which has features of novelty and advantage.

Figure 1 is a vertical sectional view of the form on the line -'aaof Fig. 2. Fig. 2 is an end view with one of the parts drawn inward. Fig. 3 is an end view of an outside and inside form with the parts locked. Fig. 4 is an end view of a square form.

The device is a form to be used in con crete work, solid, tile or brick work, etc., and is so made that it may be easily removed after using. In the manner in which it is constructed it can be readily assembled and as readily taken down so as to be used as often as desired. It'is composed of a number of sections, four being preferably used and marked 1, 2, 3, and 4 in the drawing. Each section is made up of a number of parts 5 bound together by the rib 6. The ends of the rib segments are reinforced by the plates -7 which contain a double V shaped slot -8 so constructed that when the various parts are assembled these respective apertures may be brought together so as to be locked by the keys 9 thus making one continuous rib and firmly binding the entire form together. When it is desired to take down the form, the keys 9- may be removed and the section -1 drawn inward as shown in Fig. 2- whence the whole form will easily collapse.

I find that the construction shown is the most easily collapsible of any known when assembled rigidly without keys or extra braces. The section 1 is so arranged that its sides diverge inwardly and thus allow it to be readily removed when desired. The sides of section 3 are preferably in line with the sides of section 1 thus producing a wedge-like portion-through the middle of the form.

I do not wish to confine myself to the exact construction shown herein, but claim any variations which produce the same results. The sides of sections l and 3- may be constructed at different angles with the radius of the form, those of section 3 being radial if desired. The form may be used not only for round or square work, such as shown in the drawings, but for that of any other shape and may be used for vertical or horizontal pipes such as sewers, catch basins, etc. used as an outside or an inside form or both: one method of constructing an outside form being shown in Fig. -3- where it is combined with an inside form.

The mold or form comprises two primary segments 2- and 4l and two keying segments -l and 3 fitting laterally together to present a substantially circular structure; the terminal faces of each segment being preferably in a common plane and being separated difierent distances. The keying segments are of different sizes, one of which l has its side faces inwardly divergent and the other 3- has its side faces inwardly convergent. As so constructed they fit between the terminal faces of the primary segments, forming a compact solid whole.

As the form is assembled the sections while they are being put-in place do not hinge but each one remains perfectly rigid while the others are being applied. This is due partly to its construction and partly to the method of locking the same. In the same manner it will hold itself rigid while being taken down. The parts of the square form may be assembled in irregular ways if desired.

Claim.

A form composing two opposing primary segments, the terminal faces respectively of which are separated,difi'erent distances, the faces of each segment being in a common plane, and keying segments of different sizes having their side faces convergent in the same direction and fitting into the spaces between the terminals of the respective primary segments.

In testimony whereof I afiix my signature in presence of two witnesses.

MERRILL S. JACKSON.

Witnesses:

ANNA A. BOLGER, .JoHN W. J or.

Furthermore it may loe 

